In this paper, a polymer optical fiber (POF) sensing solution to monitor the pressure induced in the foot plantar surface is investigated. The paper shows the design and implementation of a platform with an array of 5 polymer optical fiber Bragg gratings (POFBGs) placed in key points to monitor the pressure on the foot surface during gait cycles and the body center mass displacements. The results showed a great response compared with solutions using silica optical fibers. A much high sensitivity and repeatability were achieved using the CYTOP fiber as well as proving that the advantages of POF is a viable and useful solution for this type of application for a future implementation of an integrated “in-shoe” CYTOP POFBGs sensor network.

Border Gateway Protocol (BGP) enables world-wide Internet connectivity and its inherent non-secure characteristics,
together with the nonexistence of a trustable identity that correlates IP network prefixes with the
Autonomous Systems (AS) allowed to announce them, opens the way to attacks or misconfiguration on a
world-wide scale. Since corporate customers do not have access to the whole routing information used by
Internet Service Providers (ISP), they can not act against these kind of attacks and must only rely on the ISP
to promptly detect and take measures to mitigate them. This paper presents a world-wide distributed probing
platform, with a simple and very low cost implementation, that can be used to detect traffic routing variations.
Upon detection, the corporate customer can locally deploy security policies while notifying its network service
provider(s) and requesting for further actions.

The availability of relatively capable and inexpensive hardware components has made it feasible to consider
large-scale systems of autonomous aquatic drones for maritime tasks. In this paper, we present the CORATAM
and HANCAD projects, which focus on the fundamental challenges related to communication and control in
swarms of aquatic drones. We argue for: (i) the adoption of a heterogeneous approach to communication in
which a small subset of the drones have long-range communication capabilities while the majority carry only
short-range communication hardware, and (ii) the use of decentralized control to facilitate inherent robustness
and scalability. A heterogeneous communication system and decentralized control allow for the average
drone to be kept relatively simple and therefore inexpensive. To assess the proposed methodology, we are currently
building 25 prototype drones from off-the-shelf components. We present the current hardware designs
and discuss the results of simulation-based experiments involving swarms of up to 1,000 aquatic drones that
successfully patrolled a 20 km-long strip for 24 hours.

We investigate the impact of waveguide loss on the generation rate of quantum correlated photon-pairs through
four-wave mixing in a chalcogenide glass fiber. The obtained results are valid even when the photon-pairs are
generated in a medium with non-negligible loss, αL>> 1. The impact of the loss is quantified through the
analysis of the true, total and accidental counting rates at waveguide output. We use the coincidence-to-
accidental ratio (CAR) as a figure of merit of the photon-pair source. Results indicate that, the CAR parameter
tends to decrease with the increase of the waveguide length, until L < 1/α. However, a continuous increase of
the waveguide length tends to lead to an increase on the CAR value. In that non-negligible loss regime, αL>>1,
we are able to observe a significant decrease on the value of all coincidence counting rates. Nevertheless, that
decrease is even more pronounced on the accidental counting rate. Moreover, for waveguide length L = 10/α
we are able to obtain a CAR of the order of 70, which is higher than the CAR value for the specific case of
α = 0 with L = 2 cm, i.e. CAR=42. This indicates that the waveguide loss can improve the degree of quantum
correlation between the photon-pairs.

This work presents a sequential symbol synchronizer that was discovered by us, and is based on the clock sampling by the input data transitions. This synchronizer has two types, namely the discrete and the continuous. Each type has two versions which are the manual and the automatic. This synchronizer has an own big advantage, because its manual version adjust hasn’t critical phase. The objective is to study the synchronizers and to evaluate their output jitter UIRMS (Unit Interval Root Mean Square) versus input SNR (Signal to Noise Ratio).

This work presents a sequential symbol synchronizer, that is based on a pulse comparation, between a phase variable pulse and a reference fixed pulse. This synchronizer has two types namely the both data transitions and the positive data transitions. Each type has two versions which are the manual and the automatic. The objective is to study the synchronizers and evaluate the output jitter UIRMS (Unit Interval Root Mean Square) versus the input SNR (Signal Noise Ratio).

This paper presents two groups of synchronizers, namely the Carrier Phase Synchronizer and the Symbol Phase Synchronizer. In the first group the VCO (Voltage Controlled Oscillator) synchronizes with the input periodic signal and in the second the VCO synchronizes with a no periodic signal. Each group is studied under four topologies, namely the analog, hybrid, combinational and sequential. The objective is to evaluate the two groups with their four topologies and to observe the jitter-noise behaviours.

The detection of compromised hosts is currently performed at the network and host levels but any one of these options presents important security flaws: at the host level, antivirus, anti-spyware and personal firewalls are ineffective in the detection of hosts that are compromised via new or target-specific malicious software while at the network level network firewalls and Intrusion Detection Systems were developed to protect the network from external attacks but they were not designed to detect and protect against vulnerabilities that are already present inside the local area network. This paper presents a new approach for the identification of illicit traffic that tries to overcome some of the limitations of existing approaches, while being computationally efficient and easy to deploy. The approach is based on neural networks and is able to detect illicit traffic based on the historical traffic profiles presented by ”licit” and ”illicit” network applications. The evaluation of the proposed methodology relies on traffic traces obtained in a controlled environment and composed by licit traffic measured from normal activity of network applications and malicious traffic synthetically generated using the SubSeven backdoor. The results obtained show that the proposed methodology is able to achieve good identification results, being at the same time computationally efficient and easy to implement in real network scenarios.

A pilot sequence design for MIMO-OFDM systems is investigated where all transmit antennas share the same
sub-carriers to convey pilot symbols. The pilot sequences are endowed with phase-shifting properties, granting the receiver the possibility of extracting the impulse responses for all channels directly from the antennas’ time-domain received signals, without co-channel interference. A linear processing of the time-domain samples is all that is needed to get the channel impulse responses, resulting in an algorithm with very low computational load. The feasibility of the investigated method is substantiated by system simulation using indoor and outdoor broadband wireless channel models.

This paper presents and discusses a framework for end-to-end Quality-of-Service in a network operator environment. We focus on the inter-operator segment. Contrary to usual approaches, we consider that, in the current state-of-the-art, the interdomain QoS problem complexity resides on the business relations between administrative domains. Therefore, we attempt to decouple the technical problem of providing end-to-end traffic assurances from the business problem of setting up partnerships. We combine the two aspects to build a framework that allows a smooth integration of the inter-domain, the intra-domain and the access segments. We also provide an IntServ-over-DiffServ architecture that is able to cope with mobility scenarios.